Section 3-2: Properties of Parallel Lines
Corresponding Angles
Angles that lie on the same side of the transversal and in corresponding positions
Parallel Lines
Coplanar lines that do not intersect
Theorem 3-3: Alternate Exterior Angles Theorem
If a transversal intersects two parallel lines, then alternate exterior angles are congruent.
Theorem 3-1: Alternate Interior Angles Theorem
If a transversal intersects two parallel lines, then alternate interior angles are congruent.
Theorem 3-2: Corresponding Angles Theorem
If a transversal intersects two parallel lines, then corresponding angles are congruent.
Postulate 3-1: Same-Side Interior Angles Postulate
If a transversal intersects two parallel lines, then same-side interior angles are supplementary.
Same-side Interior Angles
Interior angles that lie on the same side of the transversal
Alternate Exterior Angles
Nonadjacent exterior angles that lie on opposite sides of the transversal
Alternate Interior Angles
Nonadjacent interior angles that lie on opposite sides of the transversal
Skew Lines
Noncoplanar lines that are not parallel and do not intersect
Parallel Planes
Planes that do not intersect
Transversal
A line that intersects two or more coplanar lines at distinct points